Any rules of thumb are welcome to us newbies.
If it's a MM day and you do not have MM (or are not using your MM that day), do NOT go into Fantasyland (or Tomorrowland, really) that morning. There's no point, the lines will be backed up with an hour's worth of people already. Take those mornings to play in other areas of the park. Or go to DCA!
Isn't Toontown early entry on Wednesdays? Ridemax told me that it is when I was doing our itinerary.
It's on 4 different days.
I personally wouldn't do MM and MTTMM on the same day. I thought about it, but realized that it would just be too much, and might make other days pale a bit. Plus, for MTTMM you do want to get in line outside TT a bit early. And by doing that, you're leaving lovely short FL lines to go stand in a line.
Since MTTMM doesn't really offer much apart from the little tiny parade and ceremony that you can't get by being at TT early on a normal day, I just wouldn't do that. On a normal day you can get there early, get in line (the stroller brigade as I have experienced it), and see the characters and ride the two rides, spend time exploring, and it's just about the same as a MTTMM day! Don't forgo the FL/TL stuff for it, and don't stay in FL/TL so late into MM that you're late to MTTMM, because then you're behind all those who were early.
We personally would like to go back in time and hang out in DCA's bug's land FIRST, before entering DL at all. The rides there are all out in the open. No scary dark relatively enclosed lines like for Alice, Pinocchio, Snow White, or even Peter Pan. You can see the lines, you can see the rides. And the "teacups" (ladybug boogie) don't seem to do the extra spin that the Fantasyland teacups do.
My family likes bug's land pretty much, hmm, more, or the same (for different reasons) as we do FL, and DCA is where we do enjoy starting sometimes and almost always leaving from.
Yikes, time is marching on and DS and I gotta get going! If I think of more I'll post it later.